1. Field of the Invention
The present invention relates to a used toner collecting apparatus of a laser printer.
2. Description of the Related Art
FIG. 1 shows a conventional laser printer. Referring to FIG. 1, the laser printer includes a corona unit 2, a charging unit 3, a laser scanning unit 4, developing units 5a, 5b, 5c, 5d to developing colors in the order of black K, yellow Y, magenta M, and cyan C, and a transferring belt 6. The respective parts are disposed along a rotating direction of a photosensitive drum 1 which is employed as a photosensitive medium.
A surface of the photosensitive drum 1 is evenly initialized to a predetermined voltage by the corona unit 2. The charging unit 3 charges the initialized surface of the photosensitive drum 1 to a predetermined electric potential. The laser-scanning unit 4 scans a laser beam selectively on the charged surface of the photosensitive drum 1 and forms an electrostatic latent image thereon in accordance with a desired image. The electrostatic latent image is developed to a desired color image as the developers 5a, 5b, 5c, 5d are overlain on one another. The color image on the surface of the photosensitive drum 1 is transferred to the transferring belt 6. Then the color image on the transferring belt 6 is transferred to a printing medium, which is delivered from a paper cassette 7 and passes between the transferring belt 6 and a backup roller 8 rotating in contact with the transferring belt 6. The color image transferred to the printing medium is then fixed while passing through a fixing unit 9.
In the meanwhile, on each surface of the photosensitive drum 1 and the transferring belt 6, there is some used toner that is left after the toner is transferred onto the transferring belt 6 or to the printing medium in the processes as described above. In order to remove the remaining used toner, used toner cleaning units 10, 12 are disposed at each one of the photosensitive drum 1 and the transferring belt 6.
In each one of the cleaning units 10, 12, the used toner removed from the photosensitive drum 1 or the transferring belt 6 is collected in a used toner collecting container along a predetermined way.
FIG. 2 shows a drawing of Japanese patent laid-open No. H11-202710 as one example of conventional used toner collecting apparatuses for collecting used toner from the photosensitive drum after developing process.
Referring to FIG. 2, used toner that is removed from the photosensitive drum (not shown) by a predetermined cleaning means (not shown) is transported to a drop pipe 16 that is disposed at one end of a transporting pipe 14 by an auger 15 which is set up in the transporting pipe 14. The drop pipe 16 is connected to an inlet 18a of a collecting container 18 that admits the used toner as the used toner drops from the drop pipe 16. The collecting container 18 includes a scattering member 19 disposed inside the collecting container 18 in a predetermined pose to disperse the dropping used toner evenly in the collecting container 18. In practice, the used toner, dropping from the inlet 18a, collides with the scattering member 19, and is dispersed evenly in the collecting container 18.
However, in the conventional used toner collecting apparatus as described above, the used toner occasionally lumps together because the used toner is pushed and moved in one direction by the auger 15 in the transporting pipe 14. A lump of used toner is not shattered even though it crashes against the scattering member 19 and drops as a lump into the collecting container 18. In this case, the collecting container 18 cannot admit the used toner efficiently because the used toner does not scatter evenly in the collecting container 18.
Also, the collecting container 18 may be is designed in various shapes in accordance with a size or a model of a laser printer. When a collecting container has a wide bottom, there is a problem that the used toner is hard to pile up evenly on the collecting container bottom if the lumped used toner is not broken finely.